Struct LfuCacheConfig 

pub struct LfuCacheConfig {
    pub capacity: NonZeroUsize,
    pub max_size: u64,
}

Configuration for an LFU (Least Frequently Used) cache.

LFU tracks the frequency of access for each item and evicts the least frequently used items when the cache reaches capacity.

Fields

• capacity: Maximum number of entries the cache can hold. Each entry has memory overhead (~64-128 bytes) for keys, pointers, and metadata.
• max_size: Maximum total size in bytes for cached values. Set this based on your memory budget, not to u64::MAX. See module docs for sizing guidance.

Sizing Recommendations

Always set meaningful values for both fields:

• In-memory cache: max_size = memory budget for values; capacity = max_size / average_value_size
• Disk-based cache: max_size = disk space allocation; capacity = max_size / average_object_size

Examples

use cache_rs::config::LfuCacheConfig;
use cache_rs::LfuCache;
use core::num::NonZeroUsize;

// 10MB cache for ~1KB average values → ~10,000 entries
let config = LfuCacheConfig {
    capacity: NonZeroUsize::new(10_000).unwrap(),
    max_size: 10 * 1024 * 1024,  // 10MB
};
let cache: LfuCache<String, Vec<u8>> = LfuCache::init(config, None);

// Small cache for tiny values (ints, bools) - capacity-limited
let config = LfuCacheConfig {
    capacity: NonZeroUsize::new(500).unwrap(),
    max_size: 64 * 1024,  // 64KB is ample for small values
};
let cache: LfuCache<&str, i32> = LfuCache::init(config, None);

Fields

capacity: NonZeroUsize

Maximum number of key-value pairs the cache can hold. Account for ~64-128 bytes overhead per entry beyond value size.

max_size: u64

Maximum total size in bytes for cached values. Set based on your memory/disk budget. Avoid using u64::MAX.

Trait Implementations

impl Clone for LfuCacheConfig

fn clone(&self) -> LfuCacheConfig

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for LfuCacheConfig

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Copy for LfuCacheConfig